Remotely-controlled distributed antenna system for railroad tunnels employing software defined amplifiers

ABSTRACT

An amplifier for a radio communications system in a shielded tunnel is disclosed. In one example, the amplifier comprises a processor configured to execute a plurality of modules comprising a gain control module and an attenuation control module. Methods and systems are further provided for controlling and monitoring amplifier characteristics.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/401,063, entitled “REMOTELY-CONTROLLED DISTRIBUTED ANTENNASYSTEM FOR RAILROAD TUNNELS EMPLOYING SOFTWARE DEFINED AMPLIFIERS,”filed on May 1, 2019. U.S. patent application Ser. No. 16/401,063 claimspriority to U.S. Provisional Application No. 62/665,420, entitled“REMOTELY-CONTROLLED DISTRIBUTED ANTENNA SYSTEM FOR RAILROAD TUNNELSEMPLOYING SOFTWARE DEFINED AMPLIFIERS”, and filed on May 1, 2018. Theentire contents of the above-identified applications are herebyincorporated by reference for all purposes.

FIELD

The present description relates generally to communication methods andsystems for use in a tunnel, and specifically by railroad trainstransiting a tunnel.

BACKGROUND AND SUMMARY

Railroad trains use wireless signals to facilitate continuous monitoringand control of the train. These signals include control signals that aresent from the lead locomotive to support locomotives to control brakingand acceleration. The support locomotives are generally spaced apart,separated by multiple railroad cars. In addition, signals are sentbetween an End-of-Train device and a Head-of-Train device to monitorbrake pressure and to ensure that the train is intact. However, thesewireless signals, which comprise ultra-high frequency (UHF) radiofrequencies, are not reliably transmitted when a train enters a shieldedenvironment, such as a tunnel. A previous solution to this problem usesa distributed antenna system comprising radiating coaxial cable andanalog bi-directional, in-line amplifiers to extend radio coverage intorailroad tunnels.

The inventors of the present disclosure have identified significantissues with the described tunnel communication system. As an example,set-up, maintenance, and troubleshooting of the tunnel communicationsystem requires the presence of on-site technical personnel both atamplifier locations inside the tunnel, and at a system head end outsidethe tunnel. Furthermore, adjustments of parameters such as amplifierattenuation, switching power, and gain may also demand on site, manualmanipulation of the system within the tunnel. Another issue includesdifficulty in gaining access to equipment inside an active railroadtunnel which may demand operational down time of a train track.

The issues may be at least partially addressed by a radio communicationsystem having a remotely-controlled distributed antenna system employingsoftware-defined amplifiers. The software-defined amplifiers (SDAs)described herein provides digital controls and expands monitoringcapabilities. The SDA also enables amplifier performance parameters,and, therefore, system performance to be remotely controlled. Inaddition, the SDA is compatible with existing tunnel communicationsystems and uses networking technology to send and receive data andtherefore may be retrofit to already existing systems. Control andmonitoring interfaces may be integrated into system head endapparatuses, and may be made as stand-alone remote devices.

The inventors have also identified and implemented aspects that may bebeneficial to technicians in the railroad radio communications systemsindustry. For example, amplifier gain levels may be set in the fieldwithout entering a tunnel. Also, an amplifier switching state, e.g.,processing of uplink vs. downlink signals, may be controlled remotely orat the system head end. Additional benefits of the radio communicationsystem include eliminating a pilot signal for setting amplifier gainlevels, and an ability to store and manipulate system operation data.Furthermore, the ability to remotely-control both attenuation settingsand amplifier uplink/downlink settings is achieved by the radiocommunication system, described herein.

Advantages provided by the software-defined amplifier of the presentdisclosure further include an ability to monitor a wide variety ofsystem statuses. For example, gain levels, including both uplink anddownlink gain may be monitored either from the system head end or from aremote location through a network connection. Similarly, technicians maymonitor power levels, such as peak downlink output power and switchingsignal RF input power. System parameters, such as RF detector voltages,and attenuation levels, including uplink and downlink attenuatorsettings, may also be monitored. In addition, system characteristicsmonitored may include SDA switching state and unit temperature.

SDA unit serial numbers can likewise be monitored so that a technicianat the head end or at a remote location may identify and isolate datafrom each individual SDA. Data from each SDA can be stored in a databasefor evaluation at a later time. Data from individual SDAs can also becompared to other SDAs in the system or to an ideal SDA performancestandard at the time of monitoring, or at a later occasion.

The monitoring and control of SDAs described herein has two levels. Afirst level comprises on-site monitoring and control at a head endlocation outside the tunnel. The tunnel may be any shielded environment.Once the system hardware is installed, commissioning, monitoring andcontrol of the system can take place at the head end location, withoutphysical presence of an operator inside of the tunnel. A second levelcomprises network-enabled monitoring and control. If a networkconnection is available at the site of the head end, monitoring andcontrol may be performed at any remote site coupled to the networkconnection. The summary above should be understood as providing anintroduction in simplified form to a selection of concepts that arefurther described in the detailed description. The summary is not meantto identify key or essential features of the claimed subject matter, thescope of which is defined uniquely by the claims that follow thedetailed description. Furthermore, the claimed subject matter is notlimited to implementations that solve any disadvantages noted above orin any part of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the tunnel monitoring system of thepresent disclosure.

FIG. 2 is a schematic diagram of an onsite tunnel monitoring system withsoftware-defined amplifiers (SDAs).

FIG. 3 is a simplified schematic of an onsite tunnel monitoring system.

FIG. 4 is a block diagram of an SDA.

FIG. 5 is a schematic diagram showing technician interaction with thetunnel monitoring system.

FIG. 6 is a method diagram depicting a process of setting an SDA gainlevel.

FIG. 7 is a method diagram depicting a process of checking an SDA gainlevel.

FIG. 8 is a schematic diagram of a logic subsystem of an SDA depicting aplurality of modules that may be used to adjust operating parameters ofthe SDA.

FIG. 9 is an example of a method for controlling SDA attenuation.

FIG. 10 is an example of a method for controlling SDA switching state.

FIG. 11 is an example of a method for controlling SDA switching signalpower.

FIG. 12 is an example of a method for controlling SDA voltage.

FIG. 13 is an example of a method for monitoring and reporting SDAtemperature.

FIG. 14 is an example of a method for monitoring and reporting SDA noisefloor.

FIG. 15 is an example of a method for SDA identification.

DETAILED DESCRIPTION

The following description relates to systems and methods for a radiocommunications system for railroad tunnels comprising aremotely-controlled distributed antenna system employingsoftware-defined amplifiers. The software defined amplifiers (SDAs)enable remote and on-site monitoring and control of the radiocommunications system. In one example, monitoring of the radiocommunications system includes the monitoring of downlink and uplinkpower levels, including peak downlink output power. Uplink and downlinkgain levels, and uplink and downlink RF detector voltages may bemonitored as well. Monitoring capabilities further include the abilityto monitor downlink and uplink attenuator settings, SDA switching state,switching signal power levels, and downlink and uplink noise floors.Monitoring may also include SDA unit serial numbers and temperatures.

In addition, in one embodiment, control capability includes controllingdownlink and uplink gain levels, downlink and uplink attenuatorsettings, and amplifier downlink/uplink settings. Control capability mayalso include controlling a system gain balance procedure from a systemhead end. Monitoring and control may take place on-site at the head endlocation outside the tunnel, or performed remotely through a networkconnection. In addition to the ability to monitor and control the SDAs,the radio communications system of the present disclosure enables remoteand on-site presetting of executable instructions, tuning, and diagnosisof the SDAs.

Referring now to FIG. 1, a schematic is provided which depicts generallycomponents of radio communications system 100. The schematic showscomponents of a radio communications system 100 that may interact bysending and receiving information from other components. Radiocommunications system 100 may include components, described furtherbelow, implemented by software on a device such as a computer or systemcontroller. The information may be digital information, but may alsoinclude analog information. Radio communications system 100 includes atleast one software-defined amplifier (SDA) 102.

Software may be defined as a set of instructions or data used to operatedevices such as computers. Software may include applications, programs,and scripts that run on a device, unlike, for example, hardware whichencompasses physical components of computers. Both executable code, suchas binary values defining processor values, and non-executable data,such as digital media, may be included in software. Thus, SDA 102 may beoperated and controlled based on software configured to provideinstructions for SDA 102 operations.

SDA 102 may be an electronic amplifier configured to intensify alow-power signal without degrading a signal-to-noise ratio. A power ofthe signal is increased by SDA 102 while impeding introduction ofadditional noise to the signal. Use of amplifiers in radio communicationsystems may offset loss of signal during transmission through a feedline, such as a coaxial cable.

The SDA 102 includes an SDA logic subsystem 104 that may include one ormore physical devices configured to execute one or more instructions.For example, SDA logic subsystem 104 may be configured to execute one ormore instructions that are part of one or more applications, services,programs, routines, libraries, objects, components, data structures, orother logical constructs. Such instructions may be implemented toperform a task, transform the state of one or more devices, or otherwisearrive at a desired result.

SDA logic subsystem 104 may include one or more microcontrollers orprocessors that are configured to execute preset instructions. Amicrocontroller may be a self-contained system with one or moreprocessors, a tangible non-transitory memory, and peripherals.Additionally or alternatively, the SDA logic subsystem 104 may includeone or more hardware or firmware logic machines configured to executehardware or firmware instructions. Processors of the SDA logic subsystem104 may be single or multi-core, and the instructions and algorithmsexecuted thereon may be configured for parallel or distributedprocessing. The SDA logic subsystem 104 may optionally includeindividual components that are distributed throughout two or moredevices, which may be remotely located and/or configured for coordinatedprocessing. One or more aspects of the SDA logic subsystem 104 may bevirtualized and executed by remotely accessible networked computingdevices, including devices configured in a cloud computingconfiguration.

The SDA logic subsystem 104 may include software applications inaddition to firmware. The SDA logic subsystem 104 may decode informationreceived from a system head end 120, from a remote user device 140, orfrom a train 160. The SDA logic subsystem 104 may also encodeinformation sent to other components of radio communications system 100.The SDA logic subsystem 104 may comprise one or multiplecomputer-related languages including machine languages and programminglanguages.

For example, the software applications may be implemented amongst aplurality of modules 801 of the SDA logic subsystem 104 providinginstructions for adjusting operating parameters of the SDA 102, as shownin a schematic block diagram 800 of the SDA logic subsystem 104 in FIG.8. As used herein, the term “module” may include a computer processor,controller, or other logic-based device that performs operations basedon instructions stored on a tangible and non-transitory computerreadable storage medium, such as a computer memory. Thus, each of theplurality of modules 801 may include a hard-wired device that performsoperations based on hard-wired logic of the device. The plurality ofmodules 801 may each represent hardware and associated instructions(e.g., software stored on a tangible and non-transitory computerreadable storage medium, such as a computer hard drive, ROM, RAM, or thelike) that perform one or more operations described herein. The hardwaremay include electronic circuits that include and/or are connected to oneor more logic-based devices, such as microprocessors, processors,controllers, or the like. Examples of methods for each of the pluralitymodules 801 are shown in FIGS. 6-7 and 9-15. It will be appreciated thatwhile the methods shown may compare operating parameters tocorresponding thresholds or preset levels, other examples may includeadjusting the operating parameters based on commanded levels or levelsadjusted by an operator and input into a system head end, such as thesystem head end 120 of FIG. 1, and transmitted to the SDA 102.

The plurality of modules 801 of the SDA logic subsystem 104 may includea gain control module 802. Gain is a ratio of output power to inputpower in an electrical network, e.g., a ratio of signal power deliveredto SDA 102 to signal power output of SDA 102. The system gain may beadjusted based on a desired signal intensity to be transmitted and/or atolerance of components of the radio communication system. Thus the gaincontrol module 802 may query a current gain level at the SDA 102,compare the gain level to a target gain level, and adjust the gainaccordingly. Examples of methods for controlling and confirming the gainlevel of the SDA 102 are shown in FIGS. 6 and 7 and described furtherbelow.

Similarly, an attenuation of the SDA 102 may be varied based on anattenuation control module 804. The SDA 102 may include one or moreattenuators, as shown in FIG. 4 and described further below. Theattenuators may be electronic devices that reduce a power of a signalwithout distorting a waveform of the signal, used to weaken a high leveloutput of a signal generator. For example, a resistance of theattenuators may be varied to regulate attenuation of the signal. Acurrent level of attenuation of the SDA 102 may be reported by theattenuation control module 804 and adjusted to a target level by theattenuation control module 804.

An example of a method 900 for adjusting an attenuation level of the SDA102 is shown in FIG. 9. Method 900 may be implemented by an SDAmicrocontroller and includes, at 902, determining the attenuation levelat attenuators of the SDA. The attenuation level may be estimated ormeasured, for example, by measuring a resistance at the attenuators. At904, the method includes comparing the measured attenuation level to arequested attenuation level. The requested attenuation level may be apreset level stored in a memory of the SDA microcontroller or a commandsent from a system head end, such as the system head end 120 of FIG. 1.If the attenuation level matches the requested level, the methodproceeds to 906 to continue SDA operation at the current attenuationlevel. If the attenuation level does not match the requested level, themethod continues to 908 to adjust the attenuation level via theattenuation control module 804 of FIG. 8. The method returns to 902 toestimate and/or measure the attenuation level.

The plurality of modules 801 may further include a switching statecontrol module 806 and a switching signal control module 808. Theswitching state control module 806 may receive information from one ormore switches of the SDA 102, as shown in FIG. 4, and report a status ofthe one or more switches, e.g., whether the switch is active andreceiving/transmitting a signal, indicating a path of signaltransmission. The activity of the one or more switches may also becontrolled by the switching state control module 806. The switchingsignal control module 808 may monitor a power level of the one or moreswitches, as measured by one or more signal detectors as shown in FIG.4, and report a current power level of the one or more switches as wellas adjust the power level of the one or more switches to a target powerlevel.

An example of a method 1000 for adjusting a switching state of the SDA102 is shown in FIG. 10. Method 1000 may be implemented by an SDAmicrocontroller and includes, at 1002, determining the switching stateof the SDA 102. The switching state may be evaluated based oninformation received from one or more switches of the SDA 102 regardingan activity of the one or more switches. At 1004, the method includescomparing the switching state to a requested switching state, e.g.,which switch is active/non-active, a direction or status of signaltransmission, etc. The requested switching state may be a preset stateor configuration stored in a memory of the SDA microcontroller or acommand sent from a system head end, such as the system head end 120 ofFIG. 1. If the switching state matches the requested switching state,the method proceeds to 1006 to continue SDA operation with the currentswitching state. If the switching state does not match the requestedlevel, the method continues to 1008 to adjust the switching state viathe switching state control module 806 of FIG. 8. The method returns to1002 to estimate and/or measure the switching state.

An example of a method 1100 for adjusting a switching signal power levelof the SDA 102 is shown in FIG. 11. Method 1100 may be implemented by anSDA microcontroller and includes, at 1102, determining the switchingsignal power level of the SDA 102 at one or more SDA switches. Theswitching signal power level may be determined, for example, bymeasuring power level at one or more signal detectors of the SDA 102. At1104, the method includes comparing the measured switching signal powerlevel to a requested switching signal power level. The requestedswitching signal power level may be a preset power level stored in amemory of the SDA microcontroller or a command sent from a system headend, such as the system head end 120 of FIG. 1. If the switching signalpower level matches the requested power level, the method proceeds to1106 to continue SDA operation at the current switching signal powerlevel. If the switching signal power level does not match the requestedlevel, the method continues to 1108 to adjust the switching signal powerlevel via the switching signal control module 808 of FIG. 8. The methodreturns to 902 to estimate and/or measure the switching signal powerlevel.

A voltage of the SDA 102 may be monitored and adjusted by a voltagecontrol module 810 receiving information from a voltage detector of theSDA 102. The plurality of modules 801 may also include a temperaturemonitoring module 812 to monitor and report a temperature of the SDA 102as determined by a temperature sensor at the SDA 102, a noise floormonitoring module 814, as well as an amplifier identification module816. The noise floor monitoring module 814 may report an inferred noisefloor based on reception of signals other than a target signal. Thenoise floor may be a sum of all noise sources, e.g., signals separatefrom the target signal that may interfere with reception andtransmission of the target signal at SDA 102. The noise floor may bedetermined based on a set of algorithms stored in a memory of the noisefloor monitoring module 814. The amplifier identification module 816 mayassociate a set of reported/monitored parameters, as determined byplurality of module 801, with a specific SDA 102 when more than one SDA102 is included. The amplifier identification module 816 may storeinformation regarding, for example, serial numbers of each SDA 102 andassign received information to each SDA 102 according to identity.

An example of a method 1200 for adjusting a voltage of the SDA 102 isshown in FIG. 12. Method 1200 may be implemented by an SDAmicrocontroller and includes, at 1202, determining the voltage of theSDA 102. The voltage may be determined, for example, by a voltagedetector arranged in the SDA 102. At 1204, the method includes comparingthe measured voltage to a requested voltage. The requested voltage maybe a preset voltage stored in a memory of the SDA microcontroller or acommand sent from a system head end, such as the system head end 120 ofFIG. 1. If the voltage matches the requested voltage, the methodproceeds to 1206 to continue SDA operation at the current voltage. Ifthe voltage does not match the requested level, the method continues to1208 to adjust the voltage via the voltage control module 810 of FIG. 8.The method returns to 1202 to estimate and/or measure the voltage.

An example of a method 1300 for monitoring a temperature of the SDA 102by the temperature monitor module 812 of FIG. 8 is shown in FIG. 13.Method 1300 may be implemented by an SDA microcontroller and includes,at 1302, determining the temperature of the SDA 102. The temperature maybe determined, for example, by a temperature sensor arranged in the SDA102. At 1304, the method includes comparing the measured temperature toa threshold temperature. The threshold temperature may be maximum heattolerance of the SDA 102, stored in a memory of the SDA microcontroller.Alternatively, the threshold temperature may be a preset temperaturelevel input by an operator at a system head end. If the thresholdtemperature does not reach the threshold temperature, the methodproceeds to 1306 to continue SDA operation at the current temperature.If the temperature does reach or exceed the threshold, the methodcontinues to 1308 to display an alert on a user interface, such as ascreen or monitor at a system head end or a remote user device. In someexamples, operation of the SDA 102 may be suspended until mitigatingactions are performed.

An example of a method 1400 for monitoring a noise floor of the SDA 102by the noise floor module 814 of FIG. 8 is shown in FIG. 14. Method 1400may be implemented by an SDA microcontroller and includes, at 1402,determining or inferring the noise floor of the SDA 102. The noise floormay be determined, for example, via calculating a sum of signals, e.g.,noise, other than a target signal to be amplified and transmitted,received at the SDA 102. At 1404, the method includes comparing theinferred noise floor to a threshold noise floor. The threshold noisefloor may be a noise floor level above a signal-to-noise to ratio whereit becomes challenging to resolve the target signal from noise. If theinferred noise floor does not reach the threshold noise floor, themethod proceeds to 1406 to continue SDA operation at the current noisefloor. If the inferred noise floor does reach or exceed the threshold,the method continues to 1408 to display an alert on a user interface,such as a screen or monitor at a system head end or a remote userdevice. In some examples, operation of the SDA 102 may be suspendeduntil mitigating actions are performed.

An example of a method 1500 for identifying the SDA 102 by the amplifieridentification module 816 of FIG. 8 is shown in FIG. 15. Method 1500 maybe implemented by an SDA microcontroller communicating with a processorat a system head end, such as the system head end 120 of FIG. 1. At1502, method 1500 includes transmitting information, collected by theSDA microprocessor from sensors and/or detectors of the SDA 102, to thesystem head end processor. The information may include operatingparameters such as a voltage, switching signal power level, attenuationlevel, etc. of the SDA 102. At 1504, the method includes querying theSDA microcontroller for a serial number identifying the specific SDA 102from which the information is collected. At 1506, the information issaved in a memory of the system head end processor associated with theserial number of the SDA 102.

Returning to FIG. 1, the SDA logic subsystem 104 may be upgraded overtime with new firmware or software applications. Such upgrades may beperformed from remote user device 140 through remote network 170, orfrom the system head end 120. An upgrade or change to the SDA logicsubsystem 104 may also be made by physically changing hardwarecomponents of a SDA 102, or by making programming language changesdirectly to a SDA 102.

The SDA logic subsystem 104 may make decisions in response to signals orinformation sent by a technician at the system head end 120 or from theremote user device 140, or from a conductor of the train 160. Forexample, a technician may send a request for information about a systemstatus, such as a switching state of the SDA 102, and the SDA logicsubsystem 104 may process the request and respond with a signal orinformation providing a response.

The SDA logic subsystem 104 may also make decisions automaticallyresponsive to preset instructions. These decisions may be related toinformation received from other radio communications system 100components, from information received from other SDAs 102, or frominformation received from the SDA 102 that the SDA logic subsystem 104is embedded within. The SDA logic subsystem 104 may also react to presetstimuli such as lengths of time. For example, the SDA logic subsystem104 may send a second signal to the system head end 120 and/or theremote user device 140 after a predetermined time after receiving afirst signal. Similarly, the SDA logic subsystem 104 may have presetexecutable instructions to send a signal to the system head end 120and/or the remote user device 140 when a temperature of the SDA 102, forexample, as measured by a temperature sensor, surpasses a predeterminedthreshold. As such, a likelihood of thermal degradation to the SDA 102is reduced. In one embodiment, the SDA logic subsystem 104 accumulatesdata over a span of time and subsequently sends the data to the systemhead end 120 or to the remote user device 140 at certain predeterminedtime intervals. Such data may include information about SDA 102performance and characteristics.

SDA 102 may include a SDA communication subsystem 106 that is configuredto communicatively couple the SDA 102 with one or more other computingor electronic devices, such as system head end 120, remote user device140, train 160, and one or more other SDAs 102. SDA communicationsubsystem 106 may include wired and/or wireless communication devicescompatible with one or more different communication protocols. Asnon-limiting examples, SDA communication subsystem 106 may be configuredfor communication via a wireless telephone network, a wireless localarea network, a wired local area network, a wireless wide area network,a wired wide area network, etc.

In some embodiments, SDA communication subsystem 106 may allow the SDA102 to send and/or receive messages to and/or from other devices via anetwork such as remote network 170 or intra-tunnel network 180. In someexamples, remote network 170 may be the public Internet. Furthermore,remote network 170 may be regarded as a private network connection andmay include, for example, a virtual private network or an encryption orother security mechanism employed over the public Internet. In someembodiments, SDA communication subsystem 106 may allow the SDA 102 tosend and/or receive messages to and/or from other devices via a networksuch as intra-tunnel network 180. Intra-tunnel network 180 may includeRF frequencies conventionally used by trains to receive and sendsignals. The intra-tunnel network 180 may also include other types ofwireless communication protocols including types of digital signalprotocols.

SDA 102 may also include an SDA amplification subsystem 108. SDAamplification subsystem 108 provides amplification for signals receivedand/or sent by SDA 102. SDA amplification subsystem 108 may comprisevarious hardware components such as amplifiers, attenuators, band passfilters, and switches. SDA amplification subsystem 108 may beelectronically connected to SDA logic subsystem 104 and SDAcommunication subsystem 106. Through these electronic connections, SDAamplification subsystem 108 may send and/or receive information toand/or from SDA logic subsystems 104 and SDA communication subsystem106. SDA amplification subsystem 108 may include sensors and/or variousdetectors such as switching signal detectors 426 as shown in FIG. 4. SDAamplification subsystem 108 is described in more detail in FIG. 5.

Radio communications system 100 also includes system head end 120, whichmay include hardware and software receiving data streams through theradio communication system 100. For example, system head end 120 may bea master facility configured to process and distribute radio signalsacross the radio communication system 100. In some examples, system headend 120 may be a terminal station which may be adjusted, operated and/ormonitored by a technician. System head end 120 may be located at or nearan installation site of SDA 102. System head end 120 may beelectronically coupled with at least one SDA 102 so that commissioning,monitoring, and/or control of at least one SDA 102 may be performed atsystem head end 120. System head end 120 may include head end (HE) logicsubsystem 122. HE Logic subsystem 122 may include both hardware andsoftware components.

HE logic subsystem 122 may include one or more microcontrollers orprocessors configured to execute software instructions and/or commandsinput manually. Additionally or alternatively, HE logic subsystem 122may include one or more hardware or firmware logic machines configuredto execute hardware, firmware, and manual instructions. Processors of HElogic subsystem 122 may be single or multi-core, and the presetinstructions executed thereon may be configured for parallel ordistributed processing.

HE logic subsystem 122 may include software applications in addition tofirmware. HE logic subsystem 122 may decode information received from anSDA 102 or from a remote user device 140. HE logic subsystem 122 mayalso encode information sent to other components of radio communicationssystem 100. HE logic subsystem 122 may comprise one or multiplecomputer-related languages including machine languages and programminglanguages. HE logic subsystem 122 may be upgraded with differentfirmware or software applications. Such upgrades may be performed from aremote user device 140 through remote network 170, or on-site at thelocation of system head end 120. An upgrade to HE logic subsystem 122may also be made by physically changing hardware components.

System head end 120 may also include head end (HE) display subsystem124. HE display subsystem 124 may include a monitor, screen, or similardevice that provides a visual representation of information. The visualrepresentation may include numbers, words, charts, graphs, and othermethods of conveying information. The information may be real-timeinformation such as a current SDA 102 switching state at the time ofviewing. The information may also comprise historical data such as SDA102 downlink power levels over a time span such as 1 hour, 24 hours, 1month or other time span. HE display subsystem 124 may also showmessages sent from and/or to remote user device 140.

System head end 120 may also include head end (HE) control subsystem126. HE control subsystem 126 allows manual interaction with SDA 102.The interaction may include monitoring and/or control of SDA 102.Information received when monitoring SDA 102 from system head end 120may be depicted by HE display subsystem 124. For example, a firsttechnician 502 as shown depicted in FIG. 5, may use HE control subsystem126 to communicate electronically with SDA 102 to monitor the switchingstate of SDA 102. In one example and described below, in monitoring theswitching state, a switching signal power level may be monitored. Thefirst technician 502 may manually input into the HE control subsystem126 a request for SDA 102 to provide information regarding the switchingstate or the switching signal power level. HE control subsystem 126 maytransfer the manually input commands to HE logic subsystem 122, whichmay translate the commands into a digital signal that is then sent byhead end (HE) communication subsystem 128 (described below) to SDA 102.The digital signal may be received by SDA communication subsystem 106,and analyzed by SDA logic subsystem 104. SDA logic subsystem 104 mayprovide a response based on preset executable logic algorithms, and sendthe requested information back via SDA communication subsystem 106. Therequested information is received by HE communication subsystem 128,decoded by HE logic subsystem 122, and displayed by HE display subsystem124.

In one embodiment, a switching signal power level is greater when SDA102 is in one switching state versus another switching state, and may beused to determine the switching state of SDA 102. Non-limiting examplesof the difference in the switching power level may be changes at or morethan 30 decibels. In some examples, the difference in the switchingpower may be a large factor, such as a factor of 1000 times greater.

In one embodiment, the SDA logic subsystem 104 is configured to provideinformation regarding the switching state of the SDA 102 upon receivinga request for the information that is input into the HE controlsubsystem 126. Additionally or alternatively, the switching state may bedetermined to a high level of confidence, such as a 95% confidence levelor higher, based on a determination of the switching signal power levelor the difference in the switching signal power level.

For example, information received from SDA 102 regarding a switchingsignal power level, and information received from SDA 102 regarding theswitching state, may be used in combination to determine switching stateand/or verify SDA 102 is functioning correctly. Automated determinationand identification of switching signal power level and/or switchingstate may provide alerts or other information to technicians. In someexamples, verification of switching signal power level and/or switchingstate may be triggered through an automatic system or query system basedon the determination. Verification of the reported strength of aswitching signal may be confirmed to correspond with the expectedstrength of a switching signal power level when SDA 102 is in thereported switching state. If the reported switching signal power levelis different from the expected power level for the reported switchingstate, additional alerts or triggers may indicate a changed condition.In some examples, technicians may verify or confirm the status conditionof the SDA 102.

System head end 120 may also include a HE communication subsystem 128.HE communication subsystem 128 may be configured to communicativelycouple system head end 120 with SDA 102, and/or with one or more othercomputing or electronic devices, such as remote user device 140. HEcommunication subsystem 128 may include wired and/or wirelesscommunication devices compatible with one or more differentcommunication protocols. As non-limiting examples, HE communicationsubsystem 128 may be configured for communication via a wirelesstelephone network, a wireless local area network, a wired local areanetwork, a wireless wide area network, a wired wide area network, etc.In some embodiments, HE communication subsystem 128 may allow SDA 102 tosend and/or receive messages to and/or from a remote user device 140 viaremote network 170.

System head end 120 may also include head end (HE) data-holdingsubsystem 130. HE data-holding subsystem 130 includes one or morephysical, non-transitory devices configured to hold data and/orinstructions executable by HE logic subsystem 122 to implement hereindescribed methods and processes. When such methods and processes areimplemented, the state of HE data-holding subsystem 130 may betransformed (for example, made to hold different data).

HE data-holding subsystem 130 may include removable media and/orbuilt-in devices. HE data-holding subsystem 130 may include opticalmemory (for example, CD, DVD, HD-DVD, Blu-Ray Disc, etc.), and/ormagnetic memory devices (for example, hard drive disk, floppy diskdrive, tape drive, MRAM, etc.), and the like. HE data-holding subsystem130 may include devices with one or more of the followingcharacteristics: volatile, nonvolatile, dynamic, static, read/write,read-only, random access, sequential access, location addressable, fileaddressable, and content addressable. In some embodiments, HE logicsubsystem 122 and HE data-holding subsystem 130 may be integrated intoone or more common devices, such as an application-specific integratedcircuit or a system on a chip.

The HE data-holding subsystem 130 includes one or more physical,non-transitory devices. In addition, in some embodiments aspects of theinvention described herein, data may be stored in remote servers and notheld by a physical device at the system head end 120 for at least afinite duration.

Radio communications system 100 may also include remote user device 140.Remote user device 140 may be located at a different location thansystem head end 120. Non-limiting examples include distances such as 1,100, or 1,000 miles away from system head end 120. In some examples,remote user device 140 may be a handheld device or a mounted deviceoperated by a technician. Remote user device 140 may be inside abuilding, or on the person of a technician, such as a second technician506 shown in FIG. 5, at a remote distance from the system head end 120.Remote user device 140 may remotely monitor and control SDA 102. Forexample, the second technician 506 of FIG. 5 may use remote user device140 to control the switching state of SDA 102 from a distant locationthrough remote network 170. Similarly, remote user device 140 may beused to monitor the temperature of SDA 102. To provide thesefunctionalities, remote user device 140 may comprise multiplesubsystems, such as remote user device (RD) logic subsystem 142, RDdisplay subsystem 144, RD control subsystem 146, RD communicationsubsystem 148, and RD data-holding subsystem 150.

RD logic subsystem 142, which may be part of remote user device 140, mayinclude one or more microcontrollers or processors configured to executesoftware instructions. Additionally or alternatively, RD logic subsystem142 may include one or more hardware or firmware logic machinesconfigured to execute hardware or firmware instructions. Processors ofRD logic subsystem 142 may be single or multi-core, and the presetinstructions and algorithms executed thereon may be configured forparallel or distributed processing.

RD logic subsystem 142 may also include software applications, inaddition to firmware, and both software and firmware may be upgradeable.RD logic subsystem 142 may decode information received from SDA 102 orfrom system head end 120. RD logic subsystem 142 may also encodeinformation sent to other components of radio communications system 100.RD logic subsystem 142 may comprise one or multiple computer-relatedlanguages including machine languages and programming languages.

Remote user device 140 may also include remote user device (RD) displaysubsystem 144. RD display subsystem 144 may include a monitor, screen,or similar device that provides a visual representation of information.The visual representation may include numbers, words, charts, graphs,and other methods of conveying information. The information may bereal-time information such as a current SDA 102 switching state at thetime of viewing. The information may also comprise historical data suchas SDA 102 downlink power levels over a time span such as 1 hour, 24hours, 1 month or other time span. RD display subsystem 144 may alsoshow messages sent from and/or to system head end 120.

Remote user device 140 may include remote user device (RD) communicationsubsystem 148. RD communication subsystem 148 may be configured tocommunicatively couple remote user device 140 with one or multiple SDAs102, or with one or more other computing or electronic devices, such assystem head end 120. RD communication subsystem 148 may include wiredand/or wireless communication devices compatible with one or moredifferent communication protocols. As non-limiting examples, RDcommunication subsystem 148 may be configured for communication via thewireless telephone network, the wireless local area network, the wiredlocal area network, the wireless wide area network, the wired wide areanetwork, etc. In some embodiments, RD communication subsystem 148 mayallow remote user device 140 to send and/or receive messages to and/orfrom other devices via a network such as remote network 170.

RD data-holding subsystem 150 may be included in remote user device 140.RD data-holding subsystem 150 includes one or more physical,non-transitory devices configured to hold data and/or instructionsexecutable by RD logic subsystem 142 to implement the herein describedmethods and processes. When such methods and processes are implemented,the state of RD data-holding subsystem 150 may be transformed (forexample, configured to hold different data).

RD data-holding subsystem 150 may include removable media and/orbuilt-in devices. RD data-holding subsystem 150 may include opticalmemory (for example, CD, DVD, HD-DVD, Blu-Ray Disc, etc.), and/ormagnetic memory devices (for example, hard drive disk, floppy diskdrive, tape drive, MRAM, etc.), and the like. RD data-holding subsystem150 may include devices with one or more of the followingcharacteristics: volatile, nonvolatile, dynamic, static, read/write,read-only, random access, sequential access, location addressable, fileaddressable, and content addressable. In some embodiments, RD logicsubsystem 142 and RD data-holding subsystem 150 may be integrated intoone or more common devices, such as an application-specific integratedcircuit or a system on a chip.

RD data-holding subsystem 150 includes one or more physical,non-transitory devices. In addition, in some embodiments, the RDdata-holding subsystem 150 may hold data in a remote location and thedata is not held by a physical device within, or electronicallyconnected to the RD data-holding subsystem 150, for at least a finiteduration.

HE and RD display subsystems 124 and 144, respectively, may be used topresent visual representation of data held by RD data-holding subsystem150. As the herein described methods and processes change the data heldby RD data-holding subsystem 150, and thus transform the state of RDdata-holding subsystem 150, the state of HE and RD display subsystems124 and 144, respectively, may likewise be transformed to visuallyrepresent changes in the underlying data. HE and RD display subsystems124 and 144, respectively, may include one or more display devicesutilizing virtually any type of technology. Such display devices may becombined with the HE and RD logic subsystems and/or RD data-holdingsubsystem 150 in a shared enclosure, or such display devices may beperipheral display devices.

Radio communications system 100 may include train 160. Train 160 may bea locomotive, travelling along a rail track, or another type of vehicle.Train 160 may be a passenger-carrying vehicle or a freight-carryingvehicle. Train 160 may by controlled by a conductor within a leadlocomotive 204 as shown in FIG. 2, by a remote conductor, or train 160may be fully autonomous. Train 160 may also be a vehicle used to testthe operation of radio communications system 100.

Train 160 may include train (TR) tunnel navigation subsystem 162, whichallows train 160 to interact with radio communications system 100. TRtunnel navigation subsystem 162 may include TR logic subsystem 164, TRcommunication subsystem 168, and/or TR display subsystem 166. TR tunnelnavigation subsystem 162 is described in more detail in the descriptionof FIG. 2.

Turning now to FIG. 2, a tunnel monitoring system 200 is shown. Thetunnel monitoring system 200 includes components of radio communicationssystem 100 such as SDA 102, system head end 120, remote user device 140,and train 160. Tunnel monitoring system 200 depicts a schematic ofcomponents of radio communications system 100 as situated relative totrain 160 and a shielded environment, e.g., a structure enclosing train160 which may block radio frequency electromagnetic radiation, such astunnel 202, which is navigated by train 160. For example, tunnelmonitoring system 200 also includes an antenna subsystem 220 which maybe communicatively coupled to one or more of the SDA 102, the systemhead end 120, and the remote user device 140.

First, a configuration of train 160 is described. Train 160 includes ahead, or control, locomotive 204, which may carry operations personnelsuch as engineers and firemen. A first set of rolling stock cars 206 islocated aft, relative to a direction of travel indicated by arrow 203,of head locomotive 204. A support locomotive 208 may be located betweenterminal ends of train 160 to provide additional tractive force to drivemotion of train 160. A second set of one or more rolling stock cars 210is arranged between support locomotive 208 and the end of train 160. Insome instances, train 160 may include six or more locomotives and ahundred or more rolling stock cars. In some embodiments, more than onesupport locomotives 208 may be coupled directly to control locomotive204.

TR navigation subsystem 162 may be implemented in train 160 and includesEnd-of-Train (EOT) device 212 at a trailing end of train 160, which maybe a radio frequency communication device configured with TRcommunication subsystem 168 of FIG. 1, adapted to send a first statussignal of the train 160 at a first predetermined interval, and receive asecond status signal. As an example, the first status signal mayindicate a location of the trailing end of train 160 relative to tunnel202. Head-of-Train (HOT) device 214 is located in lead locomotive 204 ata front end of train 160, and may also be a radio frequencycommunication device configured with TR communication subsystem 168 ofFIG. 1, adapted to send a second status signal at a second, lessfrequent, predetermined interval and receive the first status signalfrom EOT device 212. As an example, the second status signal mayindicate a location of a front end of train 160 relative to tunnel 202.

EOT and HOT devices 212, 214, each comprise a data transceiver. EOTdevice 212 transmits a signal which is received in open space by HOTdevice 214 mounted in lead locomotive 204, and may be monitored by theengineers in the control locomotive 204. HOT device 214 transmits a lessfrequent message back to EOT device 212. When train 160 is in a tunnelenvironment, such as depicted tunnel 202, without a communication systemsuch as tunnel monitoring system 200, the signal may blocked or shieldedfrom transmitting/receiving at the EOT and HOT device 212, 214.

To control support locomotive 208, there may be, in lead locomotive 204,a first control unit 216 including an encoder (for encoding controlinput signals for the control locomotive 204) and a control transmitter(for transmitting an encoded control signal generated from the encodedcontrol input signal). Each support locomotive 208 includes therein asecond control unit 218, formed of a control receiver and a controldecoder. The control receiver of the second control unit 218 receivesthe encoded control signal while the control decoder of the secondcontrol unit 218 decodes the encoded control signal into a control inputsignal that is used to control support locomotive 208.

Tunnel monitoring system 200 includes an antenna subsystem 220,configured to receive and send RF signals. Antenna subsystem 220includes a radiating coaxial cable 222, which is disposed along a length205 of tunnel 202 and extends beyond either end thereof. Cable 222 is“leaky,” e.g., cable 222 allows the RF signals carried therealong toradiate therefrom so as to be received by the various receivers in thesystem. Cable 222 may be manufactured with a ribbed surface to promotethe RF leakage effect, or cable 222 may be conventional coaxial cablethat is equipped with a RF leak-promoting device along a length of cable222, the length of cable 222 parallel with the length 205 of tunnel 202.In-line, bi-directional SDAs 102 are provided, in a preferredembodiment, at, for example, 1,000 foot intervals, along the length ofcoaxial cable 222 to maintain a high signal level throughout the lengthof tunnel 202. A first UHF antenna 230 may be located outside of one endof tunnel 202, while second and third UHF antennas 232 and 234,respectively are located outside an opposite end of tunnel 202. Secondand third antennas 232, 234 may be connected to an interface unit 236,which in turn may be connected to a monitoring store-and-forwardrepeater 238 and a control store-and-forward repeater 240. Interfaceunit 236 connects directly to antenna ports in store-and-forwardrepeaters 238, 240, each of which has a receiver portion (Rx) and atransmitter portion (Tx). Antenna subsystem 220 may be an active, ordistributed, antenna system. Antenna subsystem 220 of the presentdisclosure is operable to transmit both data and voice signals.

Bi-directional, in-line SDAs 102, which are spaced apart at intervalsalong coaxial cable 222, provide an amplification, e.g., an increase inintensity, for the RF signal carried through cable 222 that enables bothmonitoring and control of radio communications system 100 duringoperation. Bi-directional, in-line SDAs 102 provide automatic switching,e.g., transitioning between operations as shown in FIG. 4, to allow asignal to pass therethrough upon receipt of an appropriate signal.Coupling of interface 236 with bi-directional, in-line SDAs 102 may beaccomplished with one store-and-forward repeater 238 for monitoringcapabilities and one store-and-forward repeater 240 for controllingtunnel monitoring system 200.

Turning now to FIG. 3, a schematic diagram 300 depicts an embodiment ofradio communications system 100 showing communication between bothremote user device 140 and train 160, and tunnel monitoring system 200.As shown in FIG. 3, system head end 120 is connected through remotenetwork 170 with remote user device 140. System head end 120, in turn,is in communication with UHF antennas 230, 232, 234 through radiatingcoaxial cable 222. System head end 120 is also in communication withmultiple SDAs 102, also through cable 222. Remote user device 140 isfurther in communication with both SDAs 102 and UHF antennas 230, 232,234 via remote network 170 linking remote user device 140 with systemhead end 120.

FIG. 3 also shows train 160 navigating tunnel 202. Train 160 has an EOTdevice 212 and a HOT device 214. Radiating coaxial cable 222 is designedto communicate with EOT device 212 and HOT device 214 of train 160.While travelling through tunnel 202, EOT device 212 may send a signalthat is received by coaxial cable 222. The signal from EOT device 212may then be transmitted along cable 222, and received and amplified bythe SDAs 102. The signal may also be transmitted to antennas 230, 232,234. In addition, the signal may be transmitted to system head end 120and through remote network 170 to remote user device 140. The signal maybe emitted by radiating coaxial cable 222, and subsequently received byHOT device 214 of train 160.

Similarly, HOT device 214 may send a second signal that is received byradiating coaxial cable 222. The second signal may be transported to andamplified by any one or multiple SDAs 102. The second signal is relayedalong cable 222 to SDAs 102, to the antennas 230, 232, 234, and tosystem head end 120. From system head end 120, the signal may betransmitted through remote network 170 to remote user device 140. Whensuch a second signal is received by cable 222, the second signal maythen be emitted by cable 222 to be subsequently received by EOT device212.

Although not depicted in FIG. 3, signals sent by the first control unit216, as shown in FIG. 2, on the control locomotive 204 may also bereceived by coaxial cable 222. Such a signal may be transmitted alongcable 222 to any SDA 102 and amplified by any SDA 102, and subsequentlyemitted by cable 222 and received by the second control unit 218 locatedon support locomotive 208 of FIG. 2. The signal sent by the controlencoder and control transmitter of the first control unit 216 may alsobe transmitted along cable 222 to antennas 230, 232, and 234, and tosystem head end 120 and further through remote network 170 to remoteuser device 140. All signals of any type arriving at remote user device140 may be logged, e.g., stored in a memory of the remote user device140, and characteristics related to the signal, such as signal powerlevel, may be logged, in RD data-holding subsystem 150 of FIG. 1.

Turning now to FIG. 4, software-defined amplifier (SDA) 102 is describedin greater detail. SDA 102 operates under the control of software withno operator intervention. Software enables a transition from oneconfiguration to another without downtime, by automatically calculatinga set of state changes between one configuration and another andenabling an automated transition step between each step, thus achievingthe change via software.

First, the path of an uplink signal will be described. A signal may betransmitted from train 160 and may include a signal from an EOT device212, HOT device 214, or first control unit 216 of FIG. 2. For example,an airborne RF signal may be received from a set of signals 402transmitted by train 160. The signal is received and routed at firstswitch 404. The signal then passes through first band pass filter 406.Next, the signal passes through uplink variable attenuator 408. Then thesignal passes through uplink amplifier 410. As the signal progressestoward second switch 414, the signal is detected by uplink leveldetector 412. Uplink level detector 412 detects the strength of thesignal and sends information regarding the signal strength to themicrocontroller 424. The signal then reaches second switch 414 where thesignal is routed to radiating cable 222 that runs along the length ofthe tunnel.

Now, a path of a downlink signal is described. The downlink signal maybe a signal that was previously an uplink signal that was routed asdescribed and which traveled first through another SDA 102. The downlinksignal arrives at second switch 414 from radiating cable 222. On its wayto second switch 414, the signal passes switching signal detector 426that detects the switching signal's strength. Information regarding theswitching signal's strength is sent to microcontroller 424. When thesignal arrives at second switch 414, the signal is routed throughdownlink bandpass filter 416. Next, the signal travels through downlinkvariable attenuator 418. Then the signal moves through downlinkamplifier 420 and flows to first switch 404. Between downlink amplifier420 and first switch 404, the signal is detected by downlink signaldetector 422. Information about the downlink signal level is sent to themicrocontroller 424. The downlink signal passes through first switch 404and may progress to another SDA 102. Additionally, or alternatively, thesignal may be emitted by the SDA 102 to join the set of airborne signals402 traveling between SDA 102 and train 160.

Microcontroller 424 is designed to receive information such as thedownlink signal level, the uplink signal level, and the switching signallevel. Microcontroller 424 receives such information and processes theinformation independently, without human interference. After processingthe received information, microcontroller 424 sends correspondingcommands to downlink variable attenuator 418, uplink variable attenuator408, and the switch control (not shown). Microcontroller 424 may bepreset with executable instructions to issue certain commands inresponse to receiving certain information. For example, microcontroller424 may be preset with executable instructions to respond to informationregarding uplink signal power level by issuing commands to adjust thesettings of the uplink variable attenuator 408. Microcontroller 424executable instructions and algorithms may be configured as firmware andsoftware applications. Microcontroller 424 preset instructions may beupdated or changed remotely through remote network 170 or on-site atsystem head end 120.

Microcontroller 424 is in communication with tunnel monitoring system(TMS) Radio 428 such that digital information may be passed back andforth between them. TMS Radio 428 comprises hardware and software thatenables communication to be sent and received by tunnel monitoringsystem 200. The information may include monitoring and controlinformation. TMS Radio 428 also communicates through TMS RF 402, whichcomprises the set of airborne RF signals transmitted by SDA 102 andtrain 160. As such, TMS Radio 428 may be communicatively coupled to oneor more of the system head end 120 and the remote user device 140 ofFIG. 1.

SDA 102 is configured to allow a variety of monitoring operations. Inone example, information such as information regarding both downlinkgain level and uplink gain level is transmitted to either or both of asystem head end 120 and a remote user device 140. Similarly, SDA 102 maymonitor power levels such as peak downlink power output and switchingsignal RF input power. SDA 102 may also monitor voltages includingdownlink and uplink RF detector voltages and a DC voltage. SDA 102 mayfurther monitor other characteristics such as downlink and uplinkattenuator settings and downlink and uplink noise floors. Monitoring thedownlink and uplink attenuator settings may enable adjustment of theattenuator to divert and dissipate at least some of an excess amount ofpower at SDA 102. The downlink and uplink noise floors may be monitoredto infer a signal-to-noise ration of SDA 102 based on the noise floors.SDA temperature and unit serial number may be monitored to regulate heatproduced at SDA 102 by conversion from electrical energy. System headend 120 and one or multiple remote user devices 140 may be sentmonitoring data concurrently to allow monitoring capability at multiplelocations simultaneously.

The software-defined amplifier 102 of the present disclosure is alsoconfigured to allow a variety of control capabilities. For example, SDA102 may allow control of downlink and uplink gain levels, downlink anduplink attenuator settings, and an amplifier uplink/downlink setting.These controls may be enacted from either system head end 120 or fromone or more remote user devices 140 via remote network 170.

Control of a system gain balance method 600 (depicted in FIG. 6) fromsystem head end 120 is one example of a control procedure enabled by SDA102. The system gain balance method 600 may include three steps and maybe carried out by an onsite technician 502 at system head end 120.First, a leveling command may be executed at first SDA 102. Second,control repeater 240 may be keyed to send the command downstream. Third,steps 1 and 2 may be repeated for the remaining SDAs 102 in the system.A system gain balance method 600 is described in greater detail in FIG.6.

FIG. 5 is a depiction of first and second technicians 502, 506interacting with radio monitoring system 100. The figure shows the firsttechnician 502, which may be an onsite technician 502, interacting withsystem head end interface 504. System head end interface 504 may includeboth HE display subsystem 124 and HE control subsystem 126. System headend interface 504 allows onsite technician 502 to monitor and or controlone or more SDAs 102. For example, onsite technician 502 may use systemhead end interface 504 to monitor and set SDA 102 gain levels.

Onsite technician 502, when interacting with system head end interface504, may be able to monitor downlink gain and uplink gain at system headend interface 504. Onsite technician 502 may also monitor switchingsignal RF input power, peak downlink output power, downlink RF detectorvoltage, and uplink RF detector voltage. Downlink attenuator setting,and uplink attenuator setting may also be monitored. Other systemparameters and characteristics that may be monitored include downlinknoise floor, uplink noise floor, SDA 102 temperature, a DC voltage, andSDA 102 unit serial number.

System head end 120 may also include HE data-holding subsystem 130 whichmay receive monitoring information and store monitoring information forlater access. As a non-limiting example, HE data-holding subsystem 130may hold information regarding system gain levels for 24 hours, 1 week,or for another length of time, or indefinitely.

System head end 120 may include HE logic subsystem 122, which may bedesigned to organize, correlate, and/or process information stored in HEdata-holding subsystem 130. As a non-limiting example, HE logicsubsystem 122 may be configured to show gain level data organized interms of chronology, decreasing or increasing intensity, or othercharacteristic. Onsite technician 502 may use HE control subsystem 126to request information such as SDA 102 uplink gain levels duringspecified timeframes. The request may be processed by HE logic subsystem122, and the corresponding answer may be displayed by HE displaysubsystem 124.

Onsite technician 502, interacting with system head end interface 504,may also control aspects of SDA 102. Onsite technician 502 may use HEcontrol subsystem 126 to input control commands that are processed by HElogic subsystem 122 and then sent by HE communication subsystem 128 toone or more SDAs 102. For example, onsite technician 502 may command anSDA 102 to increase downlink attenuation. As another example, onsitetechnician 502 may command at least one SDA 102 to set gain levels. Theprocess of setting gain levels may include sending a message to controlrepeater 240, which subsequently sends a signal to an SDA 102 that tellsan SDA 102 to initialize Automatic Gain Control (AGC) mode for apredetermined number of seconds. Onsite technician 502 may then send amessage to the SDA 102 requesting that the SDA 102 responds withinformation regarding a gain level. The information sent by the SDA 102in response to the query regarding gain level may be displayed by HEdisplay subsystem 124.

FIG. 5 also shows second technician 506, which may be a remotetechnician 506, interacting with remote user device 140. Remote userdevice 140 may allow the same monitoring and control capabilities assystem head end 120, or greater or lesser capabilities. In someembodiments, there are multiple remote user devices 140 with equal ordiffering capabilities, and used by multiple remote technicians 506 orthe same remote technician 506.

As shown in FIG. 5, remote user device 140 is communicatively coupledwith RD data-holding subsystem 150. Information regarding radiomonitoring system 100 characteristics and performance may be store in RDdata-holding subsystem 150. Information stored in RD data-holdingsubsystem 150 may be accessed by remote technician 506, or accessed byonsite technician 502.

Although FIG. 5 depicts remote network 170 connecting one system headend 120 and one remote user device 140, many connectivity options areactually available. For example, in one embodiment, system head end 120may be communicatively coupled with multiple remote user devices 140. Inone example, multiple system head ends 120 may be communicativelycoupled with one remote user device 140. In another example, multiplesystem head ends 120 are connected by remote network 170 with multipleremote user devices 140 so that each system head end 120 and each remoteuser device 140 may communicate with any one or more other system headends 120 and/or remote user devices 140. In addition, remote network 170may or may not be connected or disconnected to various system head ends120 and remote user devices 140 after system commissioning. For example,as a new system head end 120 is built, new system head end 120 may beconnected to an existing remote network 170 that already communicativelycouples one or more system head ends 120 and one or more remote userdevices 140.

The access provided to radio monitoring system 100 by either system headend 120 or remote user device 140 may be utilized to upgrade, change, orreplace firmware and/or software applications in SDA, HE, and RD logicsubsystems 104, 122, 142. For example, remote technician 506 may installa software application in SDA 102 that modifies behavior ofmicrocontroller 424. Remote technician 506 may use remote user device140 to send the software application through remote network 170 tomodify SDA 102. Similarly, remote technician 506 may cancel or delete asoftware application through remote network 170.

A method 600 for setting gain in a system including multiple SDAs, suchas SDA 102 of FIGS. 1-5, arranged in series, is provided by FIG. 6.Method 600 shows an example method of controlling SDAs at a system headend, such as system head end 120 of FIG. 1. Method 600 may be performedby an onsite technician, such as onsite technician 502 of FIG. 5interacting with a system interface, e.g., system head end interface 504of FIG. 5. At 602, method 600 includes inputting a command at the systemhead end to set target power level and initiate AGC mode for a specifiednumber of seconds. At 604, a control repeater, e.g., control repeater240 of FIG. 2, receives the command and transmits the signal downstream(away from the control repeater) for a specified number of seconds. OneSDA receives the command and enters AGC mode for a specified number ofseconds at 606. At 608, using a repeater signal as a reference, the SDAadjusts output power to the specified target power level. AGC mode stopsat 610 and SDA settings are saved by a SDA logic subsystem, such as SDAlogic subsystem 104 of FIG. 1.

In addition to method 600 for setting gain outlined in FIG. 6, onsitetechnician 502 may, at 612, continue to method 700, as shown in FIG. 7,to verify that the SDA has successfully set gain to the predeterminedtarget level. Method 700 of FIG. 7 determines if an SDA 102 hassuccessfully set the gain level, thereby notifying a technician if anext downstream SDA is to be similarly set.

Turning now to FIG. 7, at 702, method 700 includes inputting a commandinto the system head end to request confirmation that the SDA hasachieved the target power level. At 704, a SDA communication subsystem,such as the SDA communication subsystem 106 of FIG. 1, receives thecommand. At 706 an SDA logic subsystem, such as the SDA logic subsystem104 of FIG. 1, decodes the command. The SDA logic subsystem thendetermines whether target power was achieved based on presetinstructions at 708.

If the SDA logic subsystem at 708 determines that the target power wasachieved, the method continues to 710 to encode a response. The SDAcommunications subsystem sends the response to the system head end at712. At 714, the response is received at the system head end. After theresponse affirming that the target power was achieved is received by thesystem head end, method 600 begins for the next SDA 102 at 716.

If the SDA logic subsystem at 708 determines that the target power wasnot achieved, then the method proceeds to 718 where the SDA logicsubsystem encodes a response. At 720, the SDA communications subsystemsends the response to the system head end. At 722, the system head endreceives the response notifying that the target power level was notachieved. At 724, method 600 is initiated again for the same SDA 102.Alternatively, troubleshooting operations, such as diagnostic tests, maybe implemented to determine why target power is not attained beforebeginning method 600 again.

In this way, a radio communication system for a train may be controlledremotely The radio communication system may include one or moresoftware-defined amplifiers (SDAs) to increase an intensity of aradiofrequency signal as the train travels through a shielded tunnel.The SDAs may be coupled to a system head end via a wirelesscommunication link, allowing operational parameters of the SDAs to beadjusted remotely. The remote control of the radio communication systemenables adjustments to be made to the SDA parameters without imposingdowntime on train operation or demanding manual manipulation of theSDAs, thereby increasing an efficiency of train operation.

In some embodiments, the amplifier of the present disclosure is anamplifier for use in a radio communications system used by a traintransiting a tunnel, and comprises a microcontroller, with one or moreprocessors, configured with executable instructions in a non-transitorymemory that when executed by the microcontroller enables the amplifierto be operative to receive, using the one or more processors, a requestfor performance or system characteristics information from a system headend or a remote user device; determine, using the one or moreprocessors, the requested information; transmit, using the one or moreprocessors, the information to the system head and or the remote userdevice; receive, using the one or more processors, one of a set ofcommands from the system head end or the remote user device to change anamplifier status or performance characteristic; determine, using the oneor more processors, the action that will enact the command; execute,using the one or more processors, the command; wherein the set ofcommands executable by one or more processors includes a command to setan amplifier gain level; wherein the amplifier is disposed along thelength of a radiating coaxial cable and amplifies RF signals therein;wherein the microcontroller is configured with executable instructionsin a non-transitory memory that when executed by the microcontrollerenables the microcontroller to switch an amplifier switching stateresponsive to a switching signal in the cable; adjust an uplink ordownlink attenuator setting responsive to an uplink or downlink signalpower level in the cable; and wherein the amplifier is bi-directional.

In some embodiments, the set of commands received from the system headend or the remote user device comprises at least one of a command to setan uplink signal attenuation level, a downlink signal attenuation level,an uplink signal gain level, a downlink signal gain level, an amplifierswitching state, and an amplifier voltage level. In some embodiments,the set of commands received from the system head end or the remote userdevice may include a switching signal power level command, specificallya command to set a switching signal power level.

In some embodiments, the information that the amplifier sends to thesystem head end or the remote user device comprises at least one ofinformation about a signal gain level, a signal attenuation level, anuplink signal gain level, a downlink signal gain level, an amplifierswitching state, a switching signal power level, an amplifier voltagelevel, an amplifier temperature, an uplink or downlink noise floor, andan amplifier unit serial number.

In one example, the radio communications system for use by trains in atunnel comprises an antenna subsystem for receiving and sending RFsignals. In one example, the antenna subsystem comprises a surfaceantenna located beyond the tunnel portals at either end thereof, aradiating coaxial cable located in and along the length of the tunnel,and at least one bi-directional amplifier disposed along the length ofthe cable and the amplifier amplifies RF signals therein. In someembodiments, the amplifier comprises a microcontroller, with one or moreprocessors, configured with executable instructions in a non-transitorymemory. In some embodiments, the executable instructions, when executedby the microcontroller, enable the amplifier to be operative to receive,using one or more processors, a request for information regardingperformance or system characteristics from a system head end or a remoteuser device; to determine, using one or more processors, the requestedinformation; and to transmit, using one or more processors, theinformation to the system head and or the remote user device. In someembodiments, the executable instructions, when executed by themicrocontroller, enable the amplifier to receive, using one or moreprocessors, one of a set of commands from the system head end or theremote user device to change an amplifier status or performancecharacteristic; determine, using one or more processors, the action thatwill enact the command; and execute, using one or more processors, thecommand; wherein the set of commands includes a command to set anamplifier gain level.

In some embodiments, the radio communications system further comprises asystem head end comprising a user interface comprising a monitor and acontrol subsystem comprising one or more processors configured withexecutable instructions in a non-transitory memory. In some embodiments,the executable instructions, when executed by the one or moreprocessors, enables the control subsystem to receive from the userinterface a request for information regarding an amplifier status orperformance characteristic; to encode the request into digital signals;to transmit the request to the amplifier; to receive the informationfrom the amplifier; to decode the information received from theamplifier; and to display the received information on the monitor. Insome embodiments, the executable instructions, when executed by the oneor more processors, enable the control subsystem to receive a commandfor changing the status of an amplifier status or performancecharacteristic from the user interface; encode the command into digitalsignals; and transmit the command to the amplifier. In some embodiments,the radio communications system may further comprise a remote userdevice comprising a user interface comprising a monitor and a controlsubsystem comprising one or more processors configured with executableinstructions in a non-transitory memory. In some embodiments, theexecutable directions, when executed by the one or more processors,enable the control subsystem is to receive from the user interface arequest for information regarding an amplifier status or performancecharacteristic; to encode the request into digital signals; to transmitthe request to the amplifier; to receive the information from theamplifier; to decode the received information from the amplifier; and todisplay the received information on the monitor. In some embodiments,the executable directions, when executed by the one or more processors,enable the control subsystem to receive one of a set of commands forchanging an amplifier status or performance characteristic from the userinterface; to encode the command into digital signals; and to transmitthe command to the amplifier.

In some embodiments of the radio communications system, at least one ofthe system head end and the remote user device further comprises atangible, non-transitory data storage device, and the stored data isaccessible from a user interface at the system head end or the remoteuser device. In some embodiments a plurality of the amplifiers aredisposed along the radiating coaxial cable. In some embodiments. In someembodiments, the radio communications system further comprises amonitoring store-and-forward repeater and a controllingstore-and-forward repeater communicatively coupled with the radiatingcoaxial cable, and configured to repeat monitoring and controllingsignals.

In some embodiments, the method of monitoring and controlling a traintransiting a tunnel comprises monitoring, from a system head end or aremote user device, an amplifier disposed along, and amplifying RFsignals therein, a radiating coaxial cable located in and along thelength of a tunnel; wherein the amplifier comprises a microcontroller,with one or more processors, configured with executable instructions ina non-transitory memory that when executed by the microcontrollerenables the amplifier to be operative to receive a request forinformation regarding an amplifier status or performance characteristicfrom a system head end or a remote user device; to determine therequested information; to transmit the information to the system headand or the remote user device; to receive one of a set of commands fromthe system head end or the remote user device to change an amplifierstatus or performance characteristic; to determine the action that willenact the command; to execute the command. In some embodiments, the setof commands includes a command to set an amplifier gain level.

In some embodiments, the system head end and remote user device eachcomprise a user interface and a control subsystem; wherein each of theuser interfaces comprise a monitor; and wherein each of the controlsubsystems comprise one or more processors and a non-transitory memoryconfigured with executable instructions to send requests for informationabout an amplifier performance or system characteristic, and to receiveand display the requested information. In some embodiments, theexecutable instructions further comprise instructions to send a commandfor a status change in an amplifier status or performancecharacteristic.

In some embodiments, monitoring the amplifier comprises inputting arequest for information regarding an amplifier status or performancecharacteristic into the user interface at either the system head end orthe remote user device; encoding, with the one or more processors in thecorresponding control subsystem, the request into digital signals,transmitting, with the one or more processors in the correspondingcontrol subsystem, the request to the amplifier; receiving, with themicrocontroller, the request at the amplifier; processing the requestwith the microcontroller in the amplifier; transmitting, with themicrocontroller, the requested information to the control subsystem thattransmitted the information request; decoding, with the one or moreprocessors in the corresponding control subsystem, the requestedinformation; displaying, with the one or more processors in thecorresponding control subsystem, the requested information on thecorresponding monitor.

In some embodiments, controlling the amplifier comprises inputting oneof a set of commands for changing an amplifier status or performancecharacteristic into either the system head or the remote user device;encoding, with one or more processors in the corresponding controlsubsystem, the command into digital signals; transmitting the command tothe amplifier; receiving, with the microcontroller, the command at theamplifier; determining, with the microcontroller, the action that willenact the command; and executing, with the microcontroller, the command.

In some embodiments, the set of commands further comprises at least oneof a command to set an uplink signal attenuation level, a downlinksignal attenuation level, an uplink signal gain level, a downlink signalgain level, an amplifier switching state, and an amplifier voltagelevel. As provided above, in some embodiments, the set of commandsfurther may include a command to set a switching signal power level.

In some embodiments, the information regarding an amplifier status orperformance characteristic includes at least one of information about asignal gain level, a signal attenuation level, an uplink signal gainlevel, a downlink signal gain level, an amplifier switching state, aswitching signal power level, an amplifier voltage level, an amplifiertemperature, an uplink or downlink noise floor, and an amplifier unitserial number.

In some embodiments, the amplifier microcontroller is configured withexecutable instructions in a non-transitory memory that when executed bythe microcontroller enables the microcontroller to switch an amplifierswitching state responsive to a switching signal in the cable; and toadjust an uplink or downlink attenuator setting responsive to an uplinkor downlink signal power level in the cable.

In some embodiments, the method to control a gain level comprisesinputting a command to set a target power level and initiate AutomaticGain Control (AGC) mode for a specific number of seconds into a userinterface at the system head end; receiving the command in the controlstore-and-forward repeater; using the control store-and-forward repeaterto transmit the command signal downstream for a specified number ofseconds; receiving the command in the amplifier, thereby causing theamplifier to enter into AGC mode for a specified number of seconds;using the repeater signal as a reference, the amplifier adjusts outputpower to the specified level; and ending AGC mode and saving settings.

In some embodiments, the method to monitor a gain level comprisesinputting a request for information regarding a power level into a userinterface at the system head end; receiving the request for informationin the amplifier; decoding, using one or more processors in theamplifier microcontroller, the request for information; determining,using one or more processors in the amplifier microcontroller, theappropriate response; encoding, using one or more processors in theamplifier microcontroller, the requested information; sending theinformation, using one or more processors in the amplifiermicrocontroller, to the system head end; and receiving the informationat the system head end.

In one embodiment, a bi-directional amplifier for a radio communicationssystem in a shielded environment includes one or more signal detectorspositioned along a signal transmission path of the bi-directionalamplifier, a microcontroller communicatively coupled to the one or moresignal detectors and configured with executable instructions in anon-transitory memory, that, when executed by the microcontroller,enables the microcontroller to adjust operating parameters of thebi-directional amplifier, and a radio communicatively coupled to themicrocontroller, the radio configured to receive and transmitinformation from a radio frequency monitoring system. In a first exampleof the amplifier, the executable instructions in the non-transitorymemory of the microcontroller includes a plurality of modules, eachmodule of the plurality of modules configured to control adjustment ofone operating parameter of the bi-directional amplifier upon executionof the module by the microcontroller. A second example of the amplifieroptionally includes the first example, and further includes, wherein theplurality of modules includes a gain control module, an attenuationcontrol module, a switching state module, a switching signal controlmodule, a voltage control module, a temperature monitoring module, anoise floor monitoring module, and an amplifier identification module. Athird example of the amplifier optionally includes one or more of thefirst and second examples, and further includes, wherein each module ofthe plurality of modules includes hardware and software configured tocontrol and report the operating parameter corresponding to the module.A fourth example of the amplifier optionally includes one or more of thefirst through third examples, and further includes, comprising switches,a downlink bandpass filter, downlink attenuator, a downlink amplifier,an uplink bandpass filter, an uplink attenuator, and an uplinkamplifier, arranged in series along the signal transmission path andconfigured to be adjustable based on instructions received from themicrocontroller. A fifth example of the amplifier optionally includesone or more of the first through fourth examples, and further includes,wherein the radio is coupled to the radio frequency monitoring system bya remote network linking the radio to a train, a remote user device, anda system head end of the radio frequency monitoring system. A sixthexample of the amplifier optionally includes one or more of the firstthrough fifth examples, and further includes, wherein themicrocontroller is configured to receive instructions from the systemhead end and/or the remote user device by transmission of theinstructions through the radio.

In another embodiment, a radio communication system includes at leastone antenna arranged at an end of a tunnel through which the trainnavigates, a coaxial cable extending along a length of the tunnel andcommunicatively coupled to the at least one antenna, at least onesoftware-defined amplifier (SDA) disposed along a length of the cable,and a remote network coupling the at least one antenna to a system headend and a remote user device of the radio communications system, thesystem head end configured to distribute radio frequency signals acrossthe radio communications system, and wherein the SDA includes aprocessor configured with executable instructions stored innon-transitory memory that when executed, cause the processor to controland report power gain levels and control and report attenuation levels.In a first example of the system, the at least one antenna is configuredto receive and transmit a radio frequency signal from the system headend and/or the remote user device and pass the signal through thecoaxial cable. A second example of the system optionally includes thefirst example and further includes, wherein the coaxial cable isconfigured to radiate the radio frequency signal and wherein the atleast one SDA is arranged in a transmission path of the radio frequencysignal. A third example of the system optionally includes one or more ofthe first and second examples, and further includes, wherein theexecutable instructions further comprises instructions that cause theprocessor to control and report an SDA switching state, an SDA switchingsignal power level, an SDA voltage. A fourth example of the systemoptionally includes one or more of the first through third examples, andfurther includes, wherein the executable instructions further comprisesinstructions that cause the processor to monitor and report an SDAtemperature, an SDA noise floor, and an SDA identification. A fifthexample of the system optionally includes one or more of the firstthrough fourth examples, and further includes, wherein at least one ofthe system head end and the remote user device comprises a tangible,non-transitory data storage device configured to store data receivedfrom the at least one SDA and wherein the stored data is accessible froma user interface.

In yet another embodiment, a method includes receiving, at a processorin an amplifier of a radio communications system, a request forinformation from at least one of a plurality of modules, sending, withthe processor in the amplifier, the requested information from at leastone of the plurality of modules, receiving, at the processor in theamplifier, a command to vary a behavior of at least one of the pluralityof modules, and varying, with the processor in the amplifier, thebehavior of the at least one of the plurality of modules, wherein theplurality of modules includes executable instructions configured toenable, when executed by the processor, the processor to control andreport amplifier gain level and control and report amplifier attenuationlevel. In a first example of the method, the plurality of modulesfurther comprises executable instructions enabling the processor tocontrol and report an amplifier switching state, control and report anamplifier switching signal power level, control and report amplifiervoltage parameters, monitor and report an amplifier temperature, monitorand report a signal noise floor, and monitor and report an amplifieridentity. A second example of the method optionally includes the firstexample, and further includes wherein receiving the request forinformation at the processor of the amplifier includes receiving therequest at an antenna positioned at an end of the tunnel from at leastone of a system head end or a remote user device via a remote networkand transmitting the signal along a coaxial cable to which the amplifieris coupled. A third example of the method optionally includes one ormore of the first and second examples, and further includes, whereinenabling the processor to control amplifier gain level includesinputting a command signal to set a target power level and initiate anAutomatic Gain Control mode for a specified number of seconds at a userinterface of the system head of the radio communications system, sendingthe command signal over the remote network to the antenna, the antennatransmitting information to a control store-and forward repeater,transmitting, by a processor in the control store-and-forward repeater,the command signal downstream in a transmission path of the amplifierfor a specified number of seconds, receiving the command signal at theprocessor in the amplifier, adjusting the amplifier to the AutomaticGain Control mode for the specified number of seconds, referring to thecommand signal to adjust the amplifier output signal power to a targetlevel, and saving settings of the amplifier into a non-transitory memoryof the processor in the amplifier. A fourth example of the methodoptionally includes one or more of the first through third examples, andfurther includes, wherein controlling gain level further includesconfirming the target level is attained by inputting a request forinformation regarding a signal power level at the user interface of thesystem head end, sending the request to the processor in the amplifierover the remote network, comparing the signal power level at theamplifier to the target level at the processor in the amplifier, sendingthe response from the processor in the amplifier to the system head overthe remote network, and displaying the response on the user interface ofthe system head end. A fifth example of the method optionally includesone or more of the first through fourth examples, and further includes,wherein enabling the processor to control amplifier attenuation levelincludes receiving a signal from a train over a remote network of aradio communications system at a switch of the amplifier andtransmitting the signal through a transmission path of the amplifier,the transmission path including a signal strength detectorcommunicatively coupled to the processor in the amplifier. A sixthexample of the method optionally includes one or more of the firstthrough fifth examples, and further includes, wherein enabling theprocessor to report amplifier attenuation level includes sendinginformation from the processor in the amplifier to a radio in theamplifier, the radio communicatively coupled to the processor and linkedto a system head end of the radio communications system over the remotenetwork.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

The invention claimed is:
 1. A bi-directional amplifier for a radiocommunications system in a shielded environment, comprising: one or moresignal detectors positioned along a signal transmission path of thebi-directional amplifier; a microcontroller communicatively coupled tothe one or more signal detectors and configured with executableinstructions in a non-transitory memory, that, when executed by themicrocontroller, enables the microcontroller to adjust operatingparameters of the bi-directional amplifier; and a radio communicativelycoupled to the microcontroller, the radio configured to receive andtransmit information from a radio frequency monitoring system; whereinthe executable instructions include one or more modules with hardwareand software configured to control and report an operating parametercorresponding to a module; wherein the one or more modules includes atleast one of a gain control module, an attenuation control module, aswitching state module, a switching signal control module, a voltagecontrol module, a temperature monitoring module, a noise floormonitoring module, and an amplifier identification module; and whereineach respective module of the one or more modules is configured tocontrol adjustment of one operating parameter of the bi-directionalamplifier upon execution of the respective module by themicrocontroller.
 2. The bi-directional amplifier of claim 1, furthercomprising switches, a downlink bandpass filter, downlink attenuator, adownlink amplifier, an uplink bandpass filter, an uplink attenuator, andan uplink amplifier, arranged in series along the signal transmissionpath and configured to be adjustable based on instructions received fromthe microcontroller.
 3. The bi-directional amplifier of claim 1, whereinthe radio is coupled to the radio frequency monitoring system by aremote network linking the radio to a train, a remote user device, and asystem head end of the radio frequency monitoring system.
 4. Thebi-directional amplifier of claim 3, wherein the microcontroller isconfigured to receive instructions from the system head end and/or theremote user device by transmission of the instructions through theradio.
 5. The bi-directional amplifier of claim 1, further comprising atleast one antenna arranged in the shielded environment.
 6. Thebi-directional amplifier of claim 5, further comprising a coaxial cableextending through the shielded environment and coupled to the at leastone antenna.
 7. The bi-directional amplifier of claim 1, wherein theshielded environment is a tunnel.
 8. A bi-directional amplifier for aradio communications system in a shielded environment, comprising: oneor more signal detectors positioned along a signal transmission path ofthe bi-directional amplifier; a microcontroller communicatively coupledto the one or more signal detectors and configured with executableinstructions in a non-transitory memory, that, when executed by themicrocontroller, enables the microcontroller to adjust operatingparameters of the bi-directional amplifier; and a radio communicativelycoupled to the microcontroller, the radio configured to receive andtransmit information from a radio frequency monitoring system; whereinthe executable instructions include a gain control module and anattenuation control module, each respective module with hardware andsoftware configured to control and report an operating parametercorresponding to the respective module; and wherein controlling theoperating parameter corresponding to the attenuation control moduleincludes receiving a signal from a train over a remote network of theradio communications system at a switch of the bi-directional amplifierand transmitting the signal through a transmission path of thebi-directional amplifier, the transmission path including a signalstrength detector communicatively coupled to the microcontroller in thebi-directional amplifier.
 9. The bi-directional amplifier of claim 8,wherein reporting the operating parameter corresponding to theattenuation control module includes sending information from themicrocontroller in the bi-directional amplifier to the radio in thebi-directional amplifier, the radio communicatively coupled to themicrocontroller and linked to a system head end of the radiocommunications system over the remote network.
 10. The bi-directionalamplifier of claim 8, wherein the executable instructions furtherinclude one or more of a switching state module, a switching signalmodule, and a voltage control module, each respective module withhardware and software configured to control and report an operatingparameter corresponding to the respective module.
 11. The bi-directionalamplifier of claim 8, wherein the executable instructions furtherinclude a temperature monitoring module with hardware and softwareconfigured to control and report an operating parameter corresponding tothe temperature monitoring module.
 12. The bi-directional amplifier ofclaim 8, wherein the executable instructions further include a noisefloor monitoring module with hardware and software configured to controland report an operating parameter corresponding to the noise floormonitoring module.
 13. The bi-directional amplifier of claim 8, whereinthe executable instructions further include an amplifier identificationmodule with hardware and software configured to control and report anoperating parameter corresponding to the amplifier identificationmodule.
 14. The bi-directional amplifier of claim 8, wherein controllingthe operating parameter corresponding to the gain control moduleincludes: receiving a command signal to set a target power level andinitiate an automatic gain control mode for a specified number ofseconds from a user interface of a system head end of the radiocommunications system over the remote network at an antenna of thebi-directional amplifier, the antenna transmitting information to acontrol store-and-forward repeater of the bi-directional amplifier;transmitting, by a processor in the control store-and-forward repeater,the command signal downstream in the transmission path of thebi-directional amplifier for the specified number of seconds; receivingthe command signal at the microcontroller in the bi-directionalamplifier; adjusting the bi-directional amplifier to the automatic gaincontrol mode for the specified number of seconds; referring to thecommand signal to adjust an output signal power level of thebi-directional amplifier to the target power level; and saving settingsof the bi-directional amplifier into the non-transitory memory of themicrocontroller in the bi-directional amplifier.
 15. The bi-directionalamplifier of claim 14, wherein controlling the operating parametercorresponding to the gain control module further includes confirming thetarget power level is attained by: receiving from the user interface ofthe system head end a request for information regarding a signal powerlevel over the remote network at the microcontroller in thebi-directional amplifier; comparing the signal power level at thebi-directional amplifier to the target power level at themicrocontroller in the bi-directional amplifier; determining a responsebased on the comparison at the microcontroller in the bi-directionalamplifier; sending the response from the microcontroller in thebi-directional amplifier to the system head end over the remote network;and displaying the response on the user interface of the system headend.
 16. A bi-directional amplifier for a radio communications system ina shielded environment, comprising: one or more signal detectorspositioned along a signal transmission path of the bi-directionalamplifier; a microcontroller communicatively coupled to the one or moresignal detectors and configured with executable instructions in anon-transitory memory, that, when executed by the microcontroller,enables the microcontroller to adjust operating parameters of thebi-directional amplifier; and a radio communicatively coupled to themicrocontroller, the radio configured to receive and transmitinformation from a radio frequency monitoring system; wherein theexecutable instructions include at least one of a gain control moduleand an attenuation control module, each respective module with hardwareand software configured to control and report an operating parametercorresponding to the respective module, each respective module furtherconfigured to control adjustment of one operating parameter of thebi-directional amplifier upon execution of the respective module by themicrocontroller.
 17. The bi-directional amplifier of claim 16, whereinthe executable instructions further comprise at least one of the gaincontrol module, the attenuation control module, a switching statemodule, a switching signal control module, a voltage control module, atemperature monitoring module, a noise floor monitoring module, and anamplifier identification module.
 18. The bi-directional amplifier ofclaim 16, wherein the radio frequency monitoring system is a remotenetwork configured to send and receive signals to and from a train. 19.The bi-directional amplifier of claim 16, wherein the radio frequencymonitoring system includes a system head end and a remote user device.20. The bi-directional amplifier of claim 19, wherein at least one ofthe system head end and the remote user device includes a tangible,non-transitory data storage device configured to store data receivedfrom the bi-directional amplifier and wherein the stored data isaccessible from a user interface.